The invention relates to the production of liquid hydrogen in a polygeneration system and integrated process wherein coal, oxygen, and water are input into the system and liquid hydrogen is produced as the main energy product for use as a propellant in space vehicles. As secondary products, gaseous nitrogen, electrical energy, and thermal energy are produced in the integrated process. The gaseous nitrogen is used at the launch complex site as an inert gas for purging critical environments. The electrical and thermal energy are utilized at the space center facilities for power and space heating and air conditioning requirements.
The United States space shuttle program has been successful over the years and is to further develop into a space transportation system. As the space shuttle program becomes an operational space transportation system, the cost of operations, and more specifically, cost per flight, begin to take on added significance. Although in terms of capability, the space shuttle has no peers, competition is already on the horizon in the area of commercial launch services. While the space shuttle vehicle has been an outstanding success, the task of turning the space shuttle into an efficient and cost effective operation for carrying payloads and passengers into and out of space, is a problem to which considerable attention need be given.
The space shuttle program costs involve several areas. One area of concern is propellants, especially liquid hydrogen for the space shuttle's main engines. Liquid hydrogen is currently produced in a natural gas steam reforming plant in New Orleans, La. and transported to Kennedy Space Center by vacuum insulated tanker trucks. Natural gas prices have been increasing steadily even in the face of stabilizing oil prices. The rising costs are a result of decontrolling of the natural gas prices. The result has been spiraling costs for natural gas in some areas as the cost of gas reaches market clearing prices. The net effect of this is a very confusing short-term picture for natural gas prices. The rising and unstable prices of natural gas have an adverse affect on the cost for the space shuttle operations. Every launch of the space shuttle requires four hundred eighty-five thousand (485,000) gallons of liquid hydrogen after accounting for boil-off, transfer, and loading losses. The cost of this hydrogen is directly affected by the cost increases in natural gas.
Other important considerations in the cost of liquid hydrogen are electricity and transportation costs. Electricity is an important factor in the cost to liquify the hydrogen and represents almost twenty-five percent of the delivered price of the liquid hydrogen. Transportation is equally important in the cost of liquid hydrogen to Kennedy Space Center. The cost of transporting liquid hydrogen in tanker trucks from the southeastern part of the United States to Kennedy Space Center accounts for approximately twenty-five percent of its delivered costs.
Gaseous nitrogen is a commodity needed in the launching of space shuttle vehicles. Gaseous nitrogen is supplied from an alternate source by pipeline to the Kennedy Space Center. Electricity is supplied by a local utility in the state of Florida The thermal energy is presently supplied by utilizing a boiler plant utilizing no. 6 fuel oil.
In accordance with the present invention, an integrated system and process is proposed for reducing the cost of liquid hydrogen and other commodities utilized in the space shuttle program by utilizing coal as a feed stock in an integrated process in which liquid hydrogen, gaseous nitrogen, electrical energy, and thermal energy are produced on-site at the space center.
In the early `70`s, numerous co-generation processes were proposed for the combined generation of electrical and thermal energy to achieve overall higher process efficiencies. Recently, a proposal for gasifying coal to produce electrical and thermal energy has been proposed by the Electric Power Research Institute. This system is described in a report entitled "Cool Water Coal Gasification Program First--Annual Progress Report, Interim Report, No. EPRI AP-2487, Project 1459, July, 1982."
A system has also been proposed entitled the New England Energy Park which is described in a final report entitled "New England Energy Park Feasibility Study for Alternative Fuels Production", June 23, 1982 Department of Energy Contract No. DE-FGOl-80RA50343. This process proposes the use of coal as a feed stock which is gasified to produce electrical power and methanol as a byproduct. The New England Energy Park process utilizes conventional gasification of coal with heat recovery followed by separation of acid gases. The final gas stream is split and one gas stream is delivered to a steam turbine for the generation of electrical power. The other gas stream is delivered to a shift conversion process where the amount of hydrogen gas is increased for the production of methanol and synthetic natural gas.
While the above described projects and systems are satisfactory for their intended applications, they do not provide the totality of integrated processes required for the supply of multiple energy products and commodities necessary for the launch of a space vehicle and for supporting the launch.
Accordingly, an important object of the present invention is to provide an integrated system and process for generating energy products and commodities to reduce the operational costs per flight of an ongoing space shuttle transportation program.
Another important object of the present invention is to provide an integrated polygeneration system and process for earth-based space center operations which produces liquid hydrogen as a main product for use as a propellant for the shuttle vehicle and secondary energy products and commodities which support shuttle operations.
Yet another important object of the present invention is to reduce the cost of launching space vehicles by integrating the processes on-site required for making the energy products and other commodities required for the launch.
Still another important object of the present invention is to reduce the cost of launching space vehicles by utilizing an inexpensive single source of feedstock and integrating the processes for making the energy products and other commodities required for launch from the feedstock at a single geographical location.
Still another important object of the present invention is to provide a system and process for producing multiple energy products and by-products in which the various processes are integrated and wherein the system can be switched from the production of one energy product to another so that the system is always fully utilized and relatively insensitive to program variations.